The Present Disclosure relates generally to connectors utilized in high speed applications, and more particularly, to improved high speed connectors that provide a commoning, or carrier member, for uniting the grounds of the wires in a cable terminated to the connector and holding the wires in a preselected arrangement.
The speeds of electrical devices are increasing and many electronic devices today are transmitting data at data rates of 12 to 25 Gb/sec. These electronic devices rely upon transmission lines to transmit signals between related devices or peripheral devices. These transmission lines utilize signal cables that use what are known as twin-axial wires, i.e., wires that have a pair of signal wires that are twisted together along the length of the cable. The wires are held in an insulative covering and the pair of such wires is usually encircled by an associated grounding shield, such as a metal braided tube or a conductive foil. The grounding shield is then encased by an insulating covering.
In order to maintain the electrical performance integrity with such a transmission line or cable through to the connection of an associated electronic device, it is desirable to have substantially constant impedance from the transmission line to the device circuitry to avoid large discontinuities in the system impedance. Problems in controlling the impedance of a connector at a connector mating interface are well known, and where the system impedance changes greatly, the signal strength may be reduced and some of the signal is reflected back to the signal source.
Twisted wire cable is designed to maintain a desired impedance through an electrical transmission line, and this is accomplished by maintaining a constant geometry or physical arrangement of the signal conductors and the grounding shield, including the spacing between the signal conductors and all of the grounds associated therewith. Unfortunately, an impedance drop usually is encountered in the termination area where the cable is terminated to a connector. This occurs when the signal conductors of a twisted pair are untwisted, oriented to mate with the termination portions of the cable connector and soldered thereto. It is therefore desirable to maintain a desired impedance as constant as possible throughout the connector and its termination to the cable.
When a signal cable is terminated to a connector, the twisted wires are untwisted and the outer grounding shield surrounding the wire pairs may be peeled back. This often results in moving the signal wires and/or the grounding shield out of their original geometry in which they exist in the cable. This introduces variability into the electrical performance. This rearrangement may further lead to a decoupling of the ground and signal wires from their original state and it often results in an increase of impedance of the electrical assembly in the cable-connector termination area as compared to that of the cable. This increase in impedance may exceed the tolerances designed for the connector system and lead to large impedance discontinuities for the system, which will deleteriously impact the electrical performance of the system. This variability and rearrangement changes the physical characteristics of the system in the termination area, resulting in problems caused by an undesirable change in the impedance of the system through the connector interface.
The Present Disclosure is therefore directed to a termination structure in the form of a grounding carrier that both holds the cable wires and their associated signal conductors in a preselected orientation and which provides interconnects the grounds associated with each of such wires.